PRKN and Parkinson disease: However, the role of the PINK1/Parkin pathway in vivo needs to be studied further particularly due to the fact that recent work from Larsson and colleagues could not demonstrate an in vivo role for Parkin in mitochondrial quality control in a mouse model of Parkinsonism based on dopaminergic neuron-specific loss of the mitochondrial transcription factor A (TFAM) (Van Laar et al., 2011; Sterky et al., 2011).